Drivers often use hands-free car kits to receive, conduct, and place telephone calls while in a motor vehicle. Some hands-free car kits (also called hands-free mobile phone kits or hands-free adapters) include a low-power FM transmitter to broadcast an audio signal on a certain FM channel to an existing FM receiver in the motor vehicle's radio system. Thus, when the FM radio is on and set to the proper FM channel at a reasonable volume, a user hears a ringing alert and/or a telephone conversation through the built-in sound system of the automobile.
Because the FM receiver of a motor vehicle may be off or at a low volume, or tuned to a radio station that does not match the low-power FM transmitter in the hands-free car kit, parts of telephone conversations may be lost while a user turns on the FM receiver, sets an appropriate volume, and selects the proper FM channel.
To overcome this, some hands-free mobile phone kits allow the user to switch between (1) an FM transmitter mode that uses the speakers associated with the car's FM receiver and (2) a built-in speaker mode that uses a hands-free speaker of the mobile phone itself. Still, if the car kit is in FM transmitter mode, and the nearby FM receiver is off, is at a low volume, or is tuned to the wrong FM channel, part of a telephone conversation may be lost. Thus, there is an opportunity to control intelligently the FM transmitter and the built-in speaker of a hands-free mobile phone kit so that no part of a telephone conversation is lost due to the FM receiver being off, at a low volume, or tuned to the wrong channel.
The various aspects, features, and advantages of the disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Drawings and accompanying Detailed Description.